Task $3\mathrm{.}1$ cap may be bonded to the airfoil or may be an integral part of it$.$ Ignoring all forces except the lift force, draw two diagrams showing the simplified forces on a line representing the box girder beam lengthwise, and the resulting stress levels in a schematic cross section of the beam.

Task $3\mathrm{.}2$

Derive the $6$ material performance indices for maximum bending stiffness and maximum bending strength, at minimum mass, at minimum projected area perpendicular to the air flow, and at minimum cost.

Task $3\mathrm{.}3$

Choose a realistic power output and blade length for a wind turbine, or look it up online. Provide two bubble charts to illustrate why fiber reinforced composites have good material properties for large wind turbine blades, and to illustrate why carbon fiber was until recently $($and often still is$)$ not price competitive with glass fiber. Are there other viable choices at the scale you selected?

Discuss one process in the manufacturing of wind turbine blades at this scale.

task $3\mathrm{.}4$ taller than it is wide, near the flange where the bending moment is greatest, to much wider than it is tall, near the tip of the blade where aerodynamic performance matters most. same area.

Task $3\mathrm{.}5$ other.

Task $3\mathrm{.}6$ Discuss to what extent the shape improves the performance or not.

Assessment criteria

description of the mechanical function, verbally and with force diagrams

derivation of the material performance indices

discussion of the material selection

discussion of a suitable manufacturing process

correct calculation of the area moments of inertia

calculation of the shape factor

discussion of the efficiency of the shape

presentation, clarity, and thoroughness of the explanations